The primary aim of the proposed research is to obtain information which will more precisely define the role of the regional lymph nodes (RLNs) in systemic tumor immunity and to compare their function with that of other lymphoid centers so that a more rational basis for the surgical and immunotherapeutic management of patients with cancer may be formulated. Since our previous studies have suggested the possible singular importance of RLNs in tumor immunity, it is deemed necessary that their function be concerned relative to the employment of specific or non-specific immunologic stimulants. The proposed series of investigations will also be directed toward determining whether (1) the performance of RLNs can be enhanced by specific or non-specific stimulation, (2) such enhancement increases systemic tumor immunity, (3) non-RLNs can respond to stimulation, (4) removal of RLNs with a primary tumor alters the host response to subsequent immune stimulation, (5) immune stimulation in the presence of tumor prevents reduction of immunity which has been observed to occur when RLNs are removed with the primary tumor, (6) the depression of systemic immunity observed following irradiation or chemotherapy is related to an effect of those agents on RLNs, (7) intratumor inoculation of non-specific immune stimulants influence RLNs and subsequent tumor immunity. Studies employing model systems devised with the human situation in mind will be utilized. Lymphoid center response of C3HeB/FeJ mice to several different autochthonous tumors will be ascertained by a variety of metodologies including 3HT uptake of cells, in-vivo neutralization in-vitro cytotoxicity, lymphocyte migration inhibition and histologic studies.